Pedestals for modulating film properties in atomic layer deposition (ald) substrate processing chambers

ABSTRACT

A system to deposit a film on a substrate using atomic layer deposition includes a pedestal arranged in a processing chamber to support the substrate on a top surface of the pedestal when depositing the film on the substrate. A first annular recess in the pedestal extends downwardly from the top surface of the pedestal and radially inwardly from an outer edge of the pedestal towards an outer edge of the substrate. The first annular recess has an inner diameter that is greater than a diameter of the substrate. An annular ring is made of a dielectric material and is arranged around the substrate in the first annular recess. A second annular recess in the pedestal is located under the annular ring. The second annular recess has a height and extends radially inwardly from the outer edge of the pedestal towards the outer edge of the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/802,904 filed on Feb. 8, 2019. The entire disclosure of theapplication referenced above is incorporated herein by reference.

FIELD

The present disclosure relates generally to substrate processing systemsand more particularly to pedestals for atomic layer deposition (ALD)substrate processing chambers.

BACKGROUND

The background description provided here is for the purpose of generallypresenting the context of the disclosure. Work of the presently namedinventors, to the extent it is described in this background section, aswell as aspects of the description that may not otherwise qualify asprior art at the time of filing, are neither expressly nor impliedlyadmitted as prior art against the present disclosure.

Substrate processing systems may be used to perform substrate treatmentsuch as deposition or etching of film on a substrate such as asemiconductor wafer. Substrate processing systems typically include aprocessing chamber with a substrate support (such as a pedestal, aplate, etc.) arranged therein. The substrate is arranged on thesubstrate support during treatment. A gas diffusion device such as ashowerhead may be arranged in the processing chamber to deliver anddisperse process gases and purge gases as needed.

In some applications, a film is deposited using plasma-enhanced chemicalvapor deposition (PECVD) or plasma-enhanced atomic layer deposition(PEALD). During PEALD, one or more cycles are performed to deposit afilm on the substrate. Each PEALD cycle typically includes precursordosing, dose purging, RF plasma dosing, and RF purging steps. Duringdeposition, process gas may be delivered to the processing chamber usingthe showerhead. During RF plasma dosing, RF power is supplied to theshowerhead, and the substrate support is grounded (or vice versa).

SUMMARY

A system for depositing a film on a substrate using atomic layerdeposition in a processing chamber comprises a pedestal arranged in theprocessing chamber to support the substrate on a top surface of thepedestal when depositing the film on the substrate using atomic layerdeposition in the processing chamber. A first annular recess in thepedestal extends downwardly from the top surface of the pedestal andradially inwardly from an outer edge of the pedestal towards an outeredge of the substrate. The first annular recess has an inner diameterthat is greater than a diameter of the substrate. An annular ring madeof a dielectric material is arranged around the substrate in the firstannular recess. A second annular recess in the pedestal is located underthe annular ring. The second annular recess has a predetermined heightand extends radially inwardly from the outer edge of the pedestaltowards the outer edge of the substrate.

In other features, the pedestal is made of a metal. The top surface ofthe pedestal is coated with a layer of a ceramic material. The layer hasa central region and an annular outer region. A thickness of the centralregion is less than the annular outer region.

In other features, the pedestal is made of a metal. An annular portionof the top surface of the pedestal is coated with a layer of a ceramic.A central portion of the top surface of the pedestal located within theannular portion is uncoated.

In other features, the pedestal is made of a metal. The top surface ofthe pedestal is coated with a layer of a ceramic material that extendsup to the inner diameter of the first annular recess. The layer includesa pocket having a depth that is less than a thickness of the layer andhaving a radius that is less than a radius of the substrate.

In other features, the pedestal is made of a metal. The top surface ofthe pedestal is coated with a layer of a ceramic material that extendsup to the inner diameter of the first annular recess. The layer includesa pocket having a depth that is equal to a thickness of the layer andhaving a radius less that is than a radius of the substrate.

In other features, a showerhead arranged above the pedestal in theprocessing chamber. The showerhead receives RF power when depositing thefilm on the substrate using atomic layer deposition in the processingchamber. The pedestal is grounded.

In other features, a showerhead arranged above the pedestal in theprocessing chamber. The pedestal receives RF power when depositing thefilm on the substrate using atomic layer deposition in the processingchamber. The showerhead is grounded.

In still other features, a system for depositing a film on a substrateusing atomic layer deposition in a processing chamber comprises apedestal that is made of a metal and that is arranged in the processingchamber to support the substrate on a top surface of the pedestal whendepositing the film on the substrate using atomic layer deposition inthe processing chamber. An annular recess in the pedestal extendsdownwardly from the top surface of the pedestal and radially inwardlyfrom an outer edge of the pedestal towards an outer edge of thesubstrate. The annular recess has an inner diameter that is greater thana diameter of the substrate. An annular ring made of a dielectricmaterial is arranged around the substrate in the annular recess. A layerof a ceramic material coats an annular outer region of the top surfaceof the pedestal.

In another feature, the annular outer region of the layer extends up tothe inner diameter of the annular recess.

In other features, the layer further includes a central region abuttingthe annular outer region. A thickness of the central region is less thanthe annular outer region.

In other features, the layer further includes a central region abuttingthe annular outer region. The central region is not coated with theceramic material.

In other features, the layer further includes a central region abuttingthe annular outer region. The central region includes a pocket having adepth that is less than a thickness of the layer and having a radiusthat is less than a radius of the substrate.

In other features, the layer further includes a central region abuttingthe annular outer region. The central region includes a pocket having adepth that is equal to a thickness of the layer and having a radius thatis less than a radius of the substrate.

In other features, a second annular recess in the pedestal is locatedunder the annular ring. The second annular recess has a predeterminedheight and extends radially inwardly from the outer edge of the pedestaltowards the outer edge of the substrate.

In other features, a showerhead arranged above the pedestal in theprocessing chamber. The showerhead receives RF power when depositing thefilm on the substrate using atomic layer deposition in the processingchamber. The pedestal is grounded.

In other features, a showerhead arranged above the pedestal in theprocessing chamber. The pedestal receives RF power when depositing thefilm on the substrate using atomic layer deposition in the processingchamber. The showerhead is grounded.

In still other features, a system for depositing a film on a substrateusing atomic layer deposition in a processing chamber comprises ashowerhead arranged in the processing chamber. The showerhead comprisesan internal plenum and gas through holes through which to introduce anddistribute process gases into the processing chamber. A pedestal made ofa metal is arranged directly below the showerhead in the processingchamber to support the substrate on a top surface of the pedestal whendepositing the film on the substrate using atomic layer deposition. Thepedestal is smaller than an area of the showerhead including the gasthrough holes. A layer of a ceramic material coats the top surface ofthe pedestal. The layer includes an annular outer region and a centralregion abutting the annular outer region. A pocket is arranged in thecentral region of the layer. The pocket has a depth that is less than orequal to a thickness of the annular outer region of the layer and has aradius that is less than a radius of the substrate.

In other features, the showerhead receives RF power when depositing thefilm on the substrate using atomic layer deposition in the processingchamber. The pedestal is grounded.

In other features, the pedestal receives RF power when depositing thefilm on the substrate using atomic layer deposition in the processingchamber. The showerhead is grounded.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description, the claims and the drawings. Thedetailed description and specific examples are intended for purposes ofillustration only and are not intended to limit the scope of thedisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 shows a functional block diagram of an example of a substrateprocessing system comprising an atomic layer deposition (ALD) processingchamber;

FIGS. 2A and 2B show a pedestal with a recessed (cutout) top portion toimprove film characteristics of substrates processed in the ALDprocessing chamber;

FIGS. 3A-3C show a pedestal with a ceramic coating applied on a topsurface of the pedestal to improve film characteristics of substratesprocessed in the ALD processing chamber;

FIGS. 4A-4D show various pedestal designs including combinations of therecessing and coating features shown in FIGS. 2A-3C to further improvefilm characteristics of substrates processed in the ALD processingchamber; and

FIG. 5 shows a pedestal design where the pedestal is smaller in sizethan an active area of a showerhead.

In the drawings, reference numbers may be reused to identify similarand/or identical elements.

DETAILED DESCRIPTION

The present disclosure relates to systems and methods for modulatingfilm etch performance including dry etch rates, downstream wet etchrates, film density, and refractive index. The systems and methodsinvolve modifying a form factor and a geometry of a pedestal at an edgeof the pedestal. Specifically, reducing an edge area of the pedestal canincrease focusing of plasma on a substrate and improve characteristicsof a film deposited on the substrate. In addition, applying a ceramiccoating on a top surface of the pedestal (directly below the substrate)can be effective in modulating substrate performance.

Additionally, plasma grounding can be directly proximate to thesubstrate for maximum realization of film properties including etchrates, density, and refractive index. Specifically, the grounding can bedirectly below the substrate for powered showerhead/grounded pedestalconfiguration and directly above the substrate for groundedshowerhead/powered pedestal configuration.

The systems and methods can be implemented by designing pedestals havinga substrate sized contact area in a portion of the pedestal directlybelow the substrate with a large undercut (cutout) in a portion of thepedestal outside the substrate sized contact area. The cutout increasesimpedance outside of a substrate plane. Alternatively or additionally,the systems and methods can be implemented by designing pedestals havinga substrate sized pedestal or a smaller pedestal in comparison to theshowerhead. These and other features of the pedestal designs accordingto the present disclosure are described below in detail.

The present disclosure is organized as follows. An example of an atomiclayer deposition (ALD) processing chamber is shown and described withreference to FIG. 1. A pedestal design with a top portion of thepedestal adjacent to the substrate recessing radially inwardly from theedge of the pedestal is shown and described with reference to FIGS. 2Aand 2B. A pedestal design with a ceramic coating applied on a topsurface of the pedestal is shown and described with reference to FIGS.3A-3C. Various additional pedestal designs including combinations of therecessing and coating features are shown and described with reference toFIGS. 4A-4D. An additional pedestal design is shown in FIG. 5 where thepedestal is smaller than an active area of a showerhead (i.e., areaincluding gas through holes), which is an alternative to having therecessing feature shown in FIGS. 2A and 2B.

FIG. 1 shows an example of a substrate processing system 100 including asubstrate support (e.g., a pedestal) 104. The substrate support 104 isarranged within a processing chamber 108. A substrate 112 is arranged onthe substrate support 104 during processing. In some examples, thesubstrate support 104 may be configured to minimize contact with thesubstrate 112. For example, only an outer edge of the substrate 112 maycontact an upper surface of the substrate support 104; the substrate 112may be arranged on minimum contact area (MCA) features; etc. While oneconfiguration of the substrate support 104 is shown and described forexample only, the teachings of the present disclosure can be applied tomany other substrate supports having different configurations.

A gas delivery system 120 includes gas sources 122-1, 122-2, . . . , and122-N (collectively gas sources 122) that are connected to valves 124-1,124-2, . . . , and 124-N (collectively valves 124) and mass flowcontrollers 126-1, 126-2, . . . , and 126-N (collectively MFCs 126). TheMFCs 126 control flow of gases from the gas sources 122 to a manifold128 where the gases mix. An output of the manifold 128 is supplied to ashowerhead 140. The showerhead 140 includes an internal plenum and gasthrough holes. The showerhead 140 introduces and distributes processgases via the gas through holes into the processing chamber 108.

An RF generating system 130 generates and outputs an RF voltage to theshowerhead 140 or the substrate support 104 (the other is DC grounded,AC grounded or floating). For example only, the RF generating system 130may include an RF voltage generator 132 that generates the RF voltagethat is fed by a matching network 134 to the showerhead 140 or thesubstrate support 104. Plasma is generated when process gases and RFpower are supplied to the showerhead 140.

In some examples, during each ALD cycle, an inert gas such as argon (Ar)or molecular nitrogen (N₂) may be used as primary purge gas flowingthrough the showerhead 140 in the dose purging and RF purging steps. Inaddition, molecular oxygen (O₂) or molecular nitrogen (N₂) may becontinuously flowing through the backside of the showerhead 140 assecondary purge in all ALD steps to prevent any undesirable depositionat remote areas such as backside of the showerhead 140, and the wallsand top plate of the processing chamber 108.

In some examples, the substrate support 104 may include coolant channels160. A cooling fluid is supplied to the coolant channels 160 from afluid storage 168 and a pump 170. In some examples, the substratesupport 104 may include a vented seal band (VSB) pedestal. In someexamples, the substrate support 104 may include a plurality of zones(not shown). A temperature of the substrate support 104 may becontrolled by using independently-controllable heaters 164 optionallyarranged in respective zones. When used, the heaters 164 may includeresistive or thin film heaters. A valve 178 and a pump 180 may be usedto evacuate reactants from the processing chamber 108 and/or to controlpressure in the processing chamber 108.

A controller 182 controls the flow of process gases, monitoring processparameters such as temperature, pressure, power, etc., striking andextinguishing plasma, removal of reactants, etc. The controller 182controls gas delivery from the gas delivery system 120 to supply processand/or purge gases at fixed intervals during a process. The controller182 controls pressure in the processing chamber 108 and/or evacuation ofreactants using the valve 178 and the pump 180. The controller 182controls the temperature of the substrate support 104 and the substrate112 based on temperature feedback from sensors (not shown) in thesubstrate support 104 and/or sensors (not shown) measuring coolanttemperature.

Film properties, particularly etch rates, can be significantly improvedby modifying the pedestal design in various ways as follows.Specifically, the modifications in the pedestal design described below,individually and in combination, improve focusing of the plasma on thesubstrate, which in turn improves film characteristics (e.g., etchrates).

FIG. 2A shows a pedestal design 200 comprising a pedestal 202 and afocus ring 204. The pedestal 202 is made of a metal such as aluminum.The focus ring 204 is made of a dielectric material. The pedestal 202can include any pedestal mentioned above in the description of FIG. 1.In some examples, the pedestal 202 and other pedestals described belowmay include a plurality of horizontally stacked pieces of metal (e.g.,aluminum). The pieces may have different shapes and may be brazedtogether to form the pedestal. Only a portion of a top piece of eachpedestal is shown in FIGS. 2A-5 to emphasize the details of the variouspedestal designs. The top piece has a flat upper surface on which asubstrate 208 is arranged during processing.

The pedestal 202 includes an annular recess 206 around a radially outeredge of the pedestal 202. An inner diameter of the annular recess 206 isgreater than a diameter of the substrate 208. The focus ring 204 isarranged on the annular recess 206. The focus ring 204 is also annularin shape and has a height (or thickness) d1 that is greater than aheight d2 of the annular recess 206. A top surface of the focus ring 204is arranged in a plane that is parallel to a top surface of a substrate208 arranged on the non-recessed portion of the pedestal 202. The topsurface of the focus ring 204 may be above or below the top surface ofthe substrate 208.

The focus ring 204 modifies an ionization rate and electron densityadjacent to an edge of the substrate 208. The focus ring 204 reducesunwanted plasma discontinuities in this area. The focus ring 204physically constrains movement of the substrate 208 on the pedestal 202.The focus ring 204 reduces plasmoids that may occur at an edge of thesubstrate 208 when using some gas species. The proximity of the focusring 204 at an outer diameter of the substrate 208 can reduce electrondensity and ionization rates near the edge of the substrate 208.

FIG. 2B shows a pedestal design 250 where a portion of the pedestal 202directly and immediately below the focus ring 204 is recessed radiallyinwardly. For example, material (e.g., metal such as aluminum) may beremoved from the pedestal 202 to form a pedestal 202-1. The pedestal202-1 defines a recess 252 directly and immediately under the focus ring204. The height h of the recess 252 is greater than the heights of thefocus ring 204 and the annular recess 206.

In some implementations, the recess 252 can extend radially inwardly toany point between a first vertical axis 252-1 along an outer diameter ofthe focus ring 204 (or an outer edge of the pedestal 202) and a secondvertical axis 252-2 along the annular recess 206. The first and secondvertical axes 252-1, 252-2 are perpendicular to a plane in which thesubstrate 208 lies or rests on the non-recessed top portion of thepedestal 202-1.

In some implementations, the recess 252 can extend further towards acenter of the pedestal 202-1 under the substrate 208. The extent of therecess 252 can be varied widely since the focus ring 204 is supported byother structures not shown here. Further, as shown and described withreference to FIG. 5, instead of creating the recess 252, the recess 252can be eliminated altogether and a pedestal that is smaller in size thanthe showerhead may be used instead.

A region 254 of the pedestal 202-1 where the material is removed fromthe pedestal 202-1 offers a greater electrical impedance than a portion256 of the pedestal 202-1 where the material (metal) is not removed fromthe pedestal 202-1. Accordingly, the recess 252 changes thecharacteristics of the film deposited on the substrate 208.Specifically, the recess 252 improves the focusing of the plasma on thesubstrate 208, which in turn improves film characteristics (e.g., etchrates). The height h and the extent of the recess 252 between the firstand second vertical axes 252-1, 252-2 (or radially further inward fromthe second vertical axis 252-2) can be selected based on the process tobe performed on the substrate 208 and factors including the design ofthe showerhead, and so on.

FIGS. 3A-3C show additional pedestal designs where a coating or a layerof a dielectric material such as a ceramic material is disposed on a topsurface of the pedestal (i.e., on the top metal surface of thepedestal). FIG. 3A shows a portion of the pedestal design 200 shown inFIG. 2A to emphasize a portion of the pedestal 202 where the dielectriccoating is applied. FIG. 3B shows a first pedestal design 300 with thedielectric coating. FIG. 3C shows a second pedestal design 350 with thedielectric coating.

FIG. 3B shows the first pedestal design 300 in which a dielectriccoating 302 is applied directly on a top surface 310 of the pedestal202. The substrate 208 rests directly on top of the dielectric coating302. In other words, there are no intervening layers of any materialbetween the dielectric coating 302 and the top surface 310 of thepedestal 202, and there are no intervening layers of any materialbetween the substrate 208 and the dielectric coating 302. This is truefor all of the pedestal designs shown in FIGS. 3B-5.

The dielectric coating 302 extends radially from a center of the topsurface 310 of the pedestal 202 to the annular recess 206. A thicknesst1 of the dielectric coating 302 is less than a thickness t2 of thesubstrate 208. In general, the thickness t1 of the dielectric coating302 may be less than or equal to about one hundredth of one inch. Forexample, the thickness t1 of the dielectric coating 302 is about four toeight thousandths of one inch.

In a portion of the dielectric coating 302 that is near the center ofthe top surface 310 of the pedestal 202, a circular pocket 312 having adiameter D and depth d is formed. The depth d of the pocket 312 is lessthan the thickness t1 of the dielectric coating 302. The diameter D ofthe pocket 312 is less than the diameter of the substrate 208. Thecircular pocket 312 denotes an annular trench or an annular recess andmay also be called the circular trench 312 or the circular recess 312.

The dielectric coating 302 and the pocket 312 change the characteristicsof the film deposited on the substrate 208. Specifically, the dielectriccoating 302 and the pocket 312 improve the focusing of the plasma on thesubstrate 208, which in turn improves film characteristics (e.g., etchrates). The diameter and the depth of the pocket 312 can be selectedbased on the process to be performed on the substrate 208 and factorsincluding the design of the showerhead, and so on.

FIG. 3C shows the second pedestal design 350 in which a circular pocket312-1 extends downward through the dielectric coating 302 all the way tothe top surface 310 of the pedestal 202. In other words, while thediameter of the pocket 312-1 is less than the diameter of the substrate208 similar to the pocket 312, the depth d of the pocket 312-1 is equalto the thickness t1 of the dielectric coating 302 unlike the pocket 312.

Accordingly, in a top view of the pedestal 220, the top surface 310 ofthe pedestal 202 is visible in the absence of the substrate 208. Again,the circular pocket 312-1 denotes an annular trench or an annular recessand may also be called the circular trench 312-1 or the circular recess312-1. The dielectric coating 302 and the pocket 312-1 change thecharacteristics of the film deposited on the substrate 208.Specifically, the dielectric coating 302 and the pocket 312-1 improvethe focusing of the plasma on the substrate 208, which improves filmcharacteristics (e.g., etch rates).

Stated differently, the ceramic layer may be described as having anannular outer portion and a central portion abutting the annular outerportion. The central region has a thickness less than that of theannular outer portion as shown in FIG. 3B. Alternatively, the centralregion has no coating at all as shown in FIG. 3C.

FIGS. 4A-4D show additional pedestal designs that combine the pedestaldesigns shown in FIGS. 2A-2B and the pedestal designs shown in FIGS.3B-3C. Specifically, FIGS. 4A and 4B show the pedestal design 200 shownin FIG. 2A combined with the dielectric coating and pockets shown inFIGS. 3B and 3C. FIGS. 4C and 4D show the pedestal design 250 shown inFIG. 2B combined with the dielectric coating and pockets shown in FIGS.3B and 3C. The combined designs shown in FIGS. 4A-4D further improve thefilm characteristics. Only portions of the pedestal designs are shown toillustrate the features that are being combined.

FIG. 4A shows a pedestal design 400 comprising the pedestal 202, thefocus ring 204, and the annular recess 206 shown in FIG. 2A. Inaddition, the pedestal 202 includes the dielectric coating 302 and thepocket 312 shown in FIG. 3B. The pedestal 202 does not include therecess 252 shown in FIG. 2B. The dielectric coating 302 and the pocket312 change the characteristics of the film deposited on the substrate208. Specifically, the dielectric coating 302 and the pocket 312 improvethe focusing of the plasma on the substrate 208, which improves filmcharacteristics (e.g., etch rates).

FIG. 4B shows a pedestal design 410 comprising the pedestal 202, thefocus ring 204, and the annular recess 206 shown in FIG. 2A. Inaddition, the pedestal 202 includes the dielectric coating 302 and thepocket 312-1 shown in FIG. 3C. The pedestal 202 does not include therecess 252 shown in FIG. 2B. The dielectric coating 302 and the pocket312-1 change the characteristics of the film deposited on the substrate208. Specifically, the dielectric coating 302 and the pocket 312-1improve the focusing of the plasma on the substrate 208, which improvesfilm characteristics (e.g., etch rates).

FIG. 4C shows a pedestal design 420 comprising the pedestal 202-1, thefocus ring 204, the annular recess 206, and the recess 252 shown in FIG.2B. In addition, the pedestal 202-1 includes the dielectric coating 302and the pocket 312 shown in FIG. 3B. The recess 252, the dielectriccoating 302, and the pocket 312 change the characteristics of the filmdeposited on the substrate 208. Specifically, the recess 252, thedielectric coating 302, and the pocket 312 improve the focusing of theplasma on the substrate 208, which in turn improves film characteristics(e.g., etch rates).

FIG. 4D shows a pedestal design 430 comprising the pedestal 202-1, thefocus ring 204, the annular recess 206, and the recess 252 shown in FIG.2B. In addition, the pedestal 202-1 includes the dielectric coating 302and the pocket 312-1 as shown in FIG. 3C. The recess 252, the dielectriccoating 302, and the pocket 312-1 change the characteristics of the filmdeposited on the substrate 208. Specifically, the recess 252, thedielectric coating 302, and the pocket 312-1 improve the focusing of theplasma on the substrate 208, which in turn improves film characteristics(e.g., etch rates).

In some implementations, instead of providing the recess 252 in thepedestal, a pedestal that is smaller in size than the active area of theshowerhead may be used, which makes creating the recess 252 in thepedestal unnecessary. This is schematically shown in FIG. 5. The activearea of the showerhead 140 is an inner area A within which the gasthrough holes are located. A smaller size of a pedestal 202-2 relativeto the active area A of the showerhead 140 improves the focusing of theplasma on the substrate 112, which in turn improves film characteristics(e.g., etch rates).

Additionally, while not shown, the dielectric coating 302 and thepockets 312/312-1 can be provided on the pedestal 202-2 as shown inFIGS. 3B and 3C. The smaller size of the pedestal 202-2 in combinationwith the dielectric coating 302 and the pockets 312/312-1 on thepedestal 202-2 improves the focusing of the plasma on the substrate 112,which in turn improves film characteristics (e.g., etch rates).

In the pedestal designs described above, grounding can be provided in anarea directly proximate to the substrate for maximum realization ofdesired film properties and etch rates. For example, when the showerheadis powered and the pedestal is grounded, grounding is provided in thepedestal via one or more electrical contacts located directly andimmediately below the substrate. The number of grounding contacts in thepedestal may vary. When the pedestal is powered, and the showerhead isgrounded, grounding is provided in the showerhead via one or moreelectrical contacts located directly and immediately above thesubstrate. The number of grounding contacts in the showerhead may vary.

Any of the pedestal designs described above with reference to FIGS. 2A-5can be used in the processing chamber 108 shown in FIG. 1. The pedestaldesigns increase the focusing of the plasma on the substrate andsignificantly improve film characteristics and reduce film etch rates.

Notably, the ceramic coating 302 on which the substrate rests is vastlydifferent than, and therefore incomparable to, a ceramic plate typicallyused to support substrates in many pedestals. For example, in manypedestals, the ceramic plate is arranged on a metal base plate, wherethe ceramic plate and the metal base plate form the pedestal. There aresignificant structural and functional differences between the ceramiccoating 302 and the typical ceramic plate.

Specifically, the ceramic coating 302 is only about four to eightthousandths of an inch thick while the ceramic plate is many millimetersthick. Further, while the ceramic plate is bonded to the metal baseplate using a layer of bonding material, the ceramic coating 302 is notbonded to the metal; instead, the ceramic coating 302 is sprayed on thetop surface of the metal.

More importantly, the typical ceramic plate comprises many componentswhile the ceramic coating 302 comprises none. For example, the typicalceramic plate comprises one or more heaters to heat the substrate insome designs. In contrast, the ceramic coating 302 does not include anyheaters. The typical ceramic plate comprises a clamping electrode and ade-clamping electrode in some designs. In contrast, the ceramic coating302 does not include any electrode. Further, while DC and RF biases maybe supplied to the components in the typical ceramic plate, no bias issupplied to the ceramic coating 302. Thus, the ceramic coating 302 isvastly different than, and incomparable to, the ceramic plate used inmany pedestals.

The foregoing description is merely illustrative in nature and is notintended to limit the disclosure, its application, or uses. The broadteachings of the disclosure can be implemented in a variety of forms.Therefore, while this disclosure includes particular examples, the truescope of the disclosure should not be so limited since othermodifications will become apparent upon a study of the drawings, thespecification, and the following claims. It should be understood thatone or more steps within a method may be executed in different order (orconcurrently) without altering the principles of the present disclosure.Further, although each embodiment is described as having certainfeatures, any one or more of those features described with respect toany embodiment of the disclosure can be implemented in and/or combinedwith features of any of the other embodiments, even if that combinationis not explicitly described. In other words, the described embodimentsare not mutually exclusive, and permutations of one or more embodimentswith one another remain within the scope of this disclosure.

Spatial and functional relationships between elements (for example,between modules, circuit elements, semiconductor layers, etc.) aredescribed using various terms, including “connected,” “engaged,”“coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and“disposed.” Unless explicitly described as being “direct,” when arelationship between first and second elements is described in the abovedisclosure, that relationship can be a direct relationship where noother intervening elements are present between the first and secondelements, but can also be an indirect relationship where one or moreintervening elements are present (either spatially or functionally)between the first and second elements. As used herein, the phrase atleast one of A, B, and C should be construed to mean a logical (A OR BOR C), using a non-exclusive logical OR, and should not be construed tomean “at least one of A, at least one of B, and at least one of C.”

In some implementations, a controller is part of a system, which may bepart of the above-described examples. Such systems can comprisesemiconductor processing equipment, including a processing tool ortools, chamber or chambers, a platform or platforms for processing,and/or specific processing components (a pedestal, a gas flow system,etc.). These systems may be integrated with electronics for controllingtheir operation before, during, and after processing of a semiconductorwafer or substrate. The electronics may be referred to as the“controller,” which may control various components or subparts of thesystem or systems.

The controller, depending on the processing requirements and/or the typeof system, may be programmed to control any of the processes disclosedherein, including the delivery of processing gases, temperature settings(e.g., heating and/or cooling), pressure settings, vacuum settings,power settings, RF generator settings, RF matching circuit settings,frequency settings, flow rate settings, fluid delivery settings,positional and operation settings, wafer transfers into and out of atool and other transfer tools and/or load locks connected to orinterfaced with a specific system.

Broadly speaking, the controller may be defined as electronics havingvarious integrated circuits, logic, memory, and/or software that receiveinstructions, issue instructions, control operation, enable cleaningoperations, enable endpoint measurements, and the like. The integratedcircuits may include chips in the form of firmware that store programinstructions, digital signal processors (DSPs), chips defined asapplication specific integrated circuits (ASICs), and/or one or moremicroprocessors, or microcontrollers that execute program instructions(e.g., software).

Program instructions may be instructions communicated to the controllerin the form of various individual settings (or program files), definingoperational parameters for carrying out a particular process on or for asemiconductor wafer or to a system. The operational parameters may, insome embodiments, be part of a recipe defined by process engineers toaccomplish one or more processing steps during the fabrication of one ormore layers, materials, metals, oxides, silicon, silicon dioxide,surfaces, circuits, and/or dies of a wafer.

The controller, in some implementations, may be a part of or coupled toa computer that is integrated with the system, coupled to the system,otherwise networked to the system, or a combination thereof. Forexample, the controller may be in the “cloud” or all or a part of a fabhost computer system, which can allow for remote access of the waferprocessing. The computer may enable remote access to the system tomonitor current progress of fabrication operations, examine a history ofpast fabrication operations, examine trends or performance metrics froma plurality of fabrication operations, to change parameters of currentprocessing, to set processing steps to follow a current processing, orto start a new process.

In some examples, a remote computer (e.g. a server) can provide processrecipes to a system over a network, which may include a local network orthe Internet. The remote computer may include a user interface thatenables entry or programming of parameters and/or settings, which arethen communicated to the system from the remote computer. In someexamples, the controller receives instructions in the form of data,which specify parameters for each of the processing steps to beperformed during one or more operations. It should be understood thatthe parameters may be specific to the type of process to be performedand the type of tool that the controller is configured to interface withor control.

Thus as described above, the controller may be distributed, such as bycomprising one or more discrete controllers that are networked togetherand working towards a common purpose, such as the processes and controlsdescribed herein. An example of a distributed controller for suchpurposes would be one or more integrated circuits on a chamber incommunication with one or more integrated circuits located remotely(such as at the platform level or as part of a remote computer) thatcombine to control a process on the chamber.

Without limitation, example systems may include a plasma etch chamber ormodule, a deposition chamber or module, a spin-rinse chamber or module,a metal plating chamber or module, a clean chamber or module, a beveledge etch chamber or module, a physical vapor deposition (PVD) chamberor module, a chemical vapor deposition (CVD) chamber or module, anatomic layer deposition (ALD) chamber or module, an atomic layer etch(ALE) chamber or module, an ion implantation chamber or module, a trackchamber or module, and any other semiconductor processing systems thatmay be associated or used in the fabrication and/or manufacturing ofsemiconductor wafers.

As noted above, depending on the process step or steps to be performedby the tool, the controller might communicate with one or more of othertool circuits or modules, other tool components, cluster tools, othertool interfaces, adjacent tools, neighboring tools, tools locatedthroughout a factory, a main computer, another controller, or tools usedin material transport that bring containers of wafers to and from toollocations and/or load ports in a semiconductor manufacturing factory.

What is claimed is:
 1. A system to deposit a film on a substrate usingatomic layer deposition in a processing chamber, the system comprising:a pedestal arranged in the processing chamber to support the substrateon a top surface of the pedestal when depositing the film on thesubstrate using atomic layer deposition in the processing chamber; afirst annular recess in the pedestal that extends downwardly from thetop surface of the pedestal and radially inwardly from an outer edge ofthe pedestal towards an outer edge of the substrate, wherein the firstannular recess has an inner diameter that is greater than a diameter ofthe substrate; an annular ring that is made of a dielectric material andthat is arranged around the substrate in the first annular recess; and asecond annular recess in the pedestal that is located under the annularring, wherein the second annular recess has a height and extendsradially inwardly from the outer edge of the pedestal towards the outeredge of the substrate.
 2. The system of claim 1 wherein the pedestal ismade of a metal.
 3. The system of claim 1 wherein: the top surface ofthe pedestal is coated with a layer of a ceramic material; the layer hasa central region and an annular outer region; and a thickness of thecentral region is less than the annular outer region.
 4. The system ofclaim 1 wherein: an annular portion of the top surface of the pedestalis coated with a layer of a ceramic; and a central portion of the topsurface of the pedestal located within the annular portion is uncoated.5. The system of claim 1 wherein: the top surface of the pedestal iscoated with a layer of a ceramic material that extends up to the innerdiameter of the first annular recess; and the layer includes a pockethaving a depth that is less than a thickness of the layer and having aradius that is less than a radius of the substrate.
 6. The system ofclaim 1 wherein: the top surface of the pedestal is coated with a layerof a ceramic material that extends up to the inner diameter of the firstannular recess; and the layer includes a pocket having a depth that isequal to a thickness of the layer and having a radius less that is thana radius of the substrate.
 7. The system of claim 1 further comprising:a showerhead arranged above the pedestal in the processing chamber;wherein the showerhead receives radio frequency power when depositingthe film on the substrate using atomic layer deposition in theprocessing chamber; and wherein the pedestal is grounded.
 8. The systemof claim 1 further comprising: a showerhead arranged above the pedestalin the processing chamber; wherein the pedestal receives radio frequencypower when depositing the film on the substrate using atomic layerdeposition in the processing chamber; and wherein the showerhead isgrounded.
 9. A system to deposit a film on a substrate using atomiclayer deposition in a processing chamber, the system comprising: apedestal that is made of a metal or ceramic and that is arranged in theprocessing chamber to support the substrate on a top surface of thepedestal when depositing the film on the substrate using atomic layerdeposition in the processing chamber; an annular recess in the pedestalthat extends downwardly from the top surface of the pedestal andradially inwardly from an outer edge of the pedestal towards an outeredge of the substrate, wherein the annular recess has an inner diameterthat is greater than a diameter of the substrate; an annular ring thatis made of a dielectric material and that is arranged around thesubstrate in the annular recess; and a layer of a ceramic material thatcoats an annular outer region of the top surface of the pedestal. 10.The system of claim 9 wherein the annular outer region of the layerextends up to the inner diameter of the annular recess.
 11. The systemof claim 9 wherein the layer further includes a central region abuttingthe annular outer region and wherein a thickness of the central regionis less than the annular outer region.
 12. The system of claim 9 whereinthe layer further includes a central region abutting the annular outerregion and wherein the central region is not coated with the ceramicmaterial.
 13. The system of claim 9 wherein: the layer further includesa central region abutting the annular outer region; and the centralregion includes a pocket having a depth that is less than a thickness ofthe layer and having a radius that is less than a radius of thesubstrate.
 14. The system of claim 9 wherein: the layer further includesa central region abutting the annular outer region; and the centralregion includes a pocket having a depth that is equal to a thickness ofthe layer and having a radius that is less than a radius of thesubstrate.
 15. The system of claim 9 further comprising a second annularrecess in the pedestal that is located under the annular ring, whereinthe second annular recess has a height and extends radially inwardlyfrom the outer edge of the pedestal towards the outer edge of thesubstrate.
 16. The system of claim 9 further comprising: a showerheadarranged above the pedestal in the processing chamber; wherein theshowerhead receives radio frequency power when depositing the film onthe substrate using atomic layer deposition in the processing chamber;and wherein the pedestal is grounded.
 17. The system of claim 9 furthercomprising: a showerhead arranged above the pedestal in the processingchamber; wherein the pedestal receives radio frequency power whendepositing the film on the substrate using atomic layer deposition inthe processing chamber; and wherein the showerhead is grounded.
 18. Asystem to deposit a film on a substrate using atomic layer deposition ina processing chamber, the system comprising: a showerhead arranged inthe processing chamber, the showerhead comprising an internal plenum andgas through holes through which to introduce and distribute processgases into the processing chamber; a pedestal that is made of a metaland that is arranged directly below the showerhead in the processingchamber to support the substrate on a top surface of the pedestal whendepositing the film on the substrate using atomic layer deposition,wherein the pedestal is smaller than an area of the showerhead includingthe gas through holes; a layer of a ceramic material that coats the topsurface of the pedestal, wherein the layer includes an annular outerregion and a central region abutting the annular outer region; and apocket arranged in the central region of the layer, wherein the pockethas a depth that is less than or equal to a thickness of the annularouter region of the layer and has a radius that is less than a radius ofthe substrate.
 19. The system of claim 18 wherein: the showerheadreceives radio frequency power when depositing the film on the substrateusing atomic layer deposition in the processing chamber; and thepedestal is grounded.
 20. The system of claim 18 wherein: the pedestalreceives radio frequency power when depositing the film on the substrateusing atomic layer deposition in the processing chamber; and theshowerhead is grounded.
 21. A pedestal to support a semiconductorsubstrate on a top surface of the pedestal, the pedestal comprising: anannular recess in the pedestal that extends downwardly from the topsurface of the pedestal and radially inwardly from an outer edge of thepedestal towards an outer edge of the semiconductor substrate, whereinthe annular recess has an inner diameter that is greater than a diameterof the semiconductor substrate; an annular ring that is made of adielectric material and that is arranged around the semiconductorsubstrate in the annular recess; and a layer of a ceramic material thatis disposed on an annular outer region of the top surface of thepedestal and that includes a central region abutting the annular outerregion, wherein the central region is not coated with the ceramicmaterial.
 22. The pedestal of claim 21 wherein the annular outer regionof the layer extends up to the inner diameter of the annular recess. 23.The pedestal of claim 21 further comprising a second annular recess inthe pedestal that is located under the annular ring, wherein the secondannular recess has a height and extends radially inwardly from the outeredge of the pedestal towards the outer edge of the semiconductorsubstrate.